Galanin and glypican-4 levels depending on metabolic and cardiovascular risk factors in patients with polycystic ovary syndrome

ABSTRACT Objective: Galanin is a neuropeptide which has effects not only on metabolic syndrome but also on reproduction. Glypican-4 is an adipokine associated with insulin sensitivity by interacting directly with the insulin receptor. This study evaluated serum concentrations of galanin and glypican-4 in relation with the hormonal profile as well as metabolic and cardiovascular risk factors in patients with and without polycystic ovary syndrome (PCOS). Subjects and methods: A total of 44 women with PCOS and 44 age-matched controls were eligible. Hirsutism scores, hormonal profile, metabolic and cardiovascular risk factors as well as galanin and glypican-4 levels were evaluated in each subject. Results: Women with PCOS exhibited lower levels of galanin (20.2 pg/mL versus 26.4 pg/mL, p = 0.002) and higher concentrations of glypican-4 (3.1 ng/mL versus 2.6 ng/mL, p < 0.001) than controls. Both adipokines were correlated positively with body mass index (BMI), insulin, triglyceride and Homeostasis Model Assessment (HOMA) index; glypican-4 also showed positive correlations with fasting blood glucose, free testosterone, modified Ferriman-Gallwey scores (p < 0.05). Multiple Linear Regression analyses showed that PCOS and BMI were the best predictors affecting galanin levels with a decreasing and increasing effect respectively; however BMI was the best predictor affecting glypican-4 levels with an increasing effect (p < 0.001). Conclusion: Galanin levels were lower and glypican-4 levels were higher in women with PCOS than controls. Further studies are needed to determine whether these adipokines could be used as additional markers for insulin sensitivity and lipid profile and whether they might play a role in the pathogenesis of PCOS, in which metabolic cardiovascular risks are increased.

Nutritional status alters the mRNA expressions of galanin and its receptors in taste buds of rats / 生理学报

The nutritional and metabolic status alters the peripheral taste perception and food intake by participating in the modulation of taste information integration. The taste receptors and neuropeptides in the taste buds are the important targets of this modulation process. To explore the effects of nutritional status on the expressions of galanin and its receptors in the taste buds, we compared the mRNA levels of galanin and its specific receptor GalR2 in the taste buds among the high-fat diet induced obese rats (HF), chronically restricted diet rats (CR) and control rats. The high-fat diet, half of chow diet, and normal chow diet were given to HF, CR and control groups for 6 weeks, respectively. The body weight and some metabolic indexes, including blood glucose, triglyceride and cholesterol levels were detected. The mRNA expressions of galanin and its receptors in taste buds were determined using real-time PCR. Results showed that compared with control rats, the body weights, levels of blood glucose and triglyceride were significantly elevated in HF rats; while the mRNA expressions of galanin and GalR2 were dramatically decreased. However, galanin mRNA expression in CR rats was increased to 2.3 times of that in control group. Considering the results obtained from our previous studies, we conclude that the behavioral changes in tasting choice of HF rats may be related to the expressions of galanin and GalR2 in the taste buds. The changes of galanin and GalR2 in taste buds are involved in the peripheral mechanism of nutritional status regulating taste perception and feeding behavior in rats.

Galanin's implications for post-stroke improvement / 대한해부학회지

Stroke leads to a variety of pathophysiological conditions such as ischemic infarct, cerebral inflammation, neuronal damage, cognitive decline, and depression. Many endeavors have been tried to find the therapeutic solutions to attenuate severe neuropathogenesis after stroke. Several studies have reported that a decrease in the neuropeptide regulator ‘galanin’ is associated with neuronal loss, learning and memory dysfunctions, and depression following a stroke. The present review summarized recent evidences on the function and the therapeutic potential of galanin in post-ischemic stroke to provide a further understanding of galanin's role. Hence, we suggest that galanin needs to be considered as a therapeutic factor in the alleviation of post-stroke pathologies.

Novel Pharmacological Treatment for Depression

Development of various antidepressants such as monoamine oxidase inhibitors, tricyclic antidepressants, selective serotonin reuptake inhibitors, serotonin norepinephrine reuptake inhibitors, and noradrenergic and specific serotonergic antidepressant has led to a tremendous progression of pharmaceutical treatment for depression, but still there are some limitations of current antidepressants, such as treatment-resistant depression and delayed onset of antidepressants. The pathogenesis of depression is unclear because depression is a heterogeneous disease state, and the mechanisms of antidepressants remain uncertain as well. Nevertheless, in an attempt to develop novel antidepressants, some trials have been conducted based on the potential biological mechanism discovered in the numerous research results. This review will provide information about the potential novel antidepressants and the current states of clinical studies using them. In particular, some potential novel antidepressants anti-inflammatory agents, antioxidants, anticholinergics, modulators of Hypothalamic Pituitary Adrenal Axis, glutamate, and opioid systems, as well as some neuropeptides such as susbstance P, neuropeptide Y, and galanin will be discussed.

Establishment of an N-2a cell line stably expressing mouse galanin and the effect of over-expressed galanin on the proliferation and apoptosis of N-2a cell / 中国医学科学院学报

<p><b>OBJECTIVE</b>To construct an N-2a cell line stably expressing PcDNA 3.1-platelet derived growth factor-galanin (GAL) and explore the effect of over-expressed GAL on proliferation and apoptosis of N-2a cell in vitro.</p><p><b>METHODS</b>The vector containing the target gene was transfected into N-2a cells by liposome, and cell clones stably over-expressing GAL was obtained via G418 screening. GAL mRNA and protein levels were determined by reverse transcriotion-polymerase chain reaction (RT-PCR) and Western blot. The proliferation of N-2a cells was detected by MTT.The cell cycle and apoptosis were detected by flow cytometry.</p><p><b>RESULTS</b>RT-PCT and Western blot indicated that GAL genes were highly expressed in the transfected N-2a cells (i.e.GAL-N-2a). As shown by MTT, the proliferation of the N-2a cells transfected with PcDNA 3.1-PDGF-GAL was significantly slower than the control group(P<0.05). Compared with the non-transfected cells in the control group, the N-2a cells with endogenously overexpressed GAL were arrested at the G0/G1 phases, and the over-expressed GAL protein significantly induced the N-2a cell apoptosis in a concentration-dependent fashion.</p><p><b>CONCLUSION</b>Eukaryotic expression vector PcDNA 3.1-PDGF-GAL can encode the expression of GAL in N-2a cells. Aslo, it can inhibit cell proliferation and promote the cell apoptosis.</p>

Normal Sleep in Children and Adolescents

Sleep is not just a rest for brain activity during daytime, but also has a vital function for memory consolidation after learning as well as restoration of both body and brain. While restoration of the body mainly occurs during non-rapid eye movement (NREM) sleep, especially during slow wave sleep, restoration of brain and memory consolidation occurs mainly during REM sleep. Adenosine acts as a sleep-inducing agent, so called somnogen or hypnotoxin which accumulates while awake. Sleep deprivation results in the disruption of every aspect of physical, cognitive, and behavioral function, which can be reversed only by sleep. Many neurotransmitter-secreting nuclei in the brain stem, hypothalamus, and basal forebrain are key structures for wakefulness, NREM, and REM sleep. They have been localized in the basal forebrain (acetylcholine), ventrolateral preoptic area (VLPO, GABA and galanin), tuberomamillary nucleus (TMN, histamine), lateral and posterior hypothalamus (orexin/hypocretin), reticular formation (glutamate), substantia nigra/ventral tegmental area (SN/VTA, dopamine), pedunculopontine nucleus and lateral dorsal tegmentum (PPT-LDT, acetylcholine), locus ceruleus (norepinephrine), and the raphe nuclei (serotonin). All are activated during wakefulness except VLPO which secrets GABA and galanin, which suppress other nuclei for sleep induction. Acetylcholine-secreting PPT-LDT is a major locus for REM sleep, and is inhibited by the raphe nuclei and locus ceruleus which act as REM-off neurons inducing NREM sleep. The suprachiasmatic nucleus is a pacemaker for circadian rhythms, which can be modified by bright light and melatonin. It should be emphasized that the best performance of cognitive function including reactivity, abstract thinking, creativity, memory, executive function, and accurate and efficient work as well as physical well-being is achieved by sufficient and appropriate sleep.

Regulation of neuropeptide Y, vasoactive intestinal peptide and galanin by insulin in rats

To study the regulation of neuropeptide Y, vasoactive intestinal peptide and galanin by insulin in rats. Experimental study. The study was conducted at the department of Metabolic Medicine Hammersmith hospital, Royal Postgraduate Medical School, London for on year [1996-1997]. Tissue levels of neuro peptide Y [NPY] and vaso intestinal peptide [VIP] decreased of the intestine and pancreas in insulin infused rats. NPY was also decreased significantly in hypothalamus. No significant effect on NPY in brain stem and on VIP in hypothalamus was observed. Galanin decreased significantly in intestine and hypothalamus. Galanin mRNA decreased to 57.7 +/- 8.8 percent of controls [p < 0.05] in intestine and 58.7 +/- 17.7 percent of controls in hypothalamus. Therefore insulin decreased the tissue levels of galanin by inhibiting its mRNA. It is concluded that NPY, VIP and galanin are negatively regulated by insulin. Actions of insulin on endocrine pancreas and central control of glucose homeostasis and food intake by insulin may be partly modulated through changes in these peptides. VIP acts synergistically with glucagon in the development of hyperosmolar coma in NIDDM patients. NPY and galanin increase ketone bodies formation and hyperphagia in diabetics and contribute in the development of diabetic ketoacidosis and obesity

Galanin stimulates hCG induced testicular steroidogenesis in adult but not in immature male rats.

The present study was undertaken to understand the role of galanin on testosterone secretion. Leydig cells from adult (60-80 days old) and immature (21-30 days old) rat testis were incubated with galanin (100 nM), galantide (100 nM) and Human Chorionic Gonadotropin (hCG, 25 I.U.) alone or in combinations and testosterone release was measured. It was observed that in adults, galanin failed to alter the basal testosterone release from the dispersed Leydig cells but potentiated the hCG induced testosterone release significantly. While galantide, prevented this galanin potentiating effect, but it did not alter the hCG alone induced testosterone release. On the other hand, the Leydig cells obtained from immature male rats were sensitive to hCG alone but not to galanin or galantide, both of which failed to alter the hCG induced testosterone release from these cells. Based on these results it can be postulated that galanin's role at the level of the male gonad is age dependent since its potentiating effects on hCG induced testosterone release were visible only in the adult and not in the immature male rats.

Changes of body weight and galanin in epileptic children treated with topiramate / 中华儿科杂志

<p><b>OBJECTIVE</b>Topiramate is a new broad-spectrum anti-epileptic drug. Decreased body weight and appetite are common side effects of topiramate. The side effect affects the growth and development in children greatly. Little is known about the mechanisms of topiramate-induced weight loss and decreased appetite in children with epilepsy in China and abroad. galanin is one of factors that affect appetite. It is a neuroendocrine peptide and play an important role in the control of appetite and body weight in the mechanism of hormone release. The purpose of this study was to explore the mechanism of topiramate-induced weight loss in children with epilepsy and the relation of weight loss with change of galanin, thereby to provide evidences for improvement of quality of life, compliance to treatment and reduce side effects of growth and development in children with epilepsy.</p><p><b>METHODS</b>Totally 61 patients with especial epilepsy were enrolled into this study and the disease was defined by clinical manifestations and electroencephalography (EEG). Among them 32 cases had generalized seizures and 29 had local seizures. Sixteen normal children were enrolled as control group. The patients' age ranged from 0.5 to 14 (4.76 +/- 4.05) years and the patients were instructed to take 0.5 - 1 mg/kg of topiramate per day, with 0.5 - 1 mg/kg every 3 - 5 d increased to maximum of 3 - 8 mg/kg per day. Patients continued receiving the doses for 4 months. All patients' serum galanin levels and body height and weight and hepatic function were detected before and after antiepileptic drugs treatment. The galanin was detected by using radioimmunoassay.</p><p><b>RESULTS</b>After treatment with topiramate (61 cases) for 4 months, plasma galanin [(22.01 +/- 8.12) pg/ml] declined as compared with baseline [(26.56 +/- 9.35) pg/ml, t = 2.85, P < 0.01] in children with epilepsy. Twenty-two of 61 patients lost weight, their plasma galanin concentration was significantly lower [(26.51 +/- 10.00) pg/ml vs. (20.45 +/- 8.09) pg/ml, t = 2.91, P < 0.01], but there was no significant change in the weight-gained patients (39/61) and control group (n = 16). In children with epilepsy, the mean value of body weight decreased as compared with the pre-treatment values, but the difference was not significant; however, the body-mass index (BMI) was significantly lower than that obtained before treatment (t = 8.628, P < 0.01). Eighteen of 22 patients who lost weight had decreased appetite, but only five of 39 patients who gained weight showed decreased appetite (chi(2) = 28.50, P < 0.001). The mean value of plasma galanin declined after treatment in patients (23 cases) with decreased appetite [(18.35 +/- 7.80) pg/ml vs. (27.28 +/- 6.90) pg/ml, t = 4.84, P < 0.001]; while plasma galanin did not change significantly after treatment in patients (38 cases) without decreased appetite [(24.23 +/- 7.66) pg/ml vs. (26.12 +/- 5.49) pg/ml, t = 1.04, P > 0.05].</p><p><b>CONCLUSION</b>Topiramate treatment may lower the body weight and reduce appetite in part of children with epilepsy which may be mediated by the reduced plasma galanin level.</p>

Immortalized rat astrocyte strain genetically modified by rat preprogalanin gene / 华中科技大学学报（医学）（英德文版）

To construct an immortalized rat astrocyte strain genetically modified by rat preprogalanin gene (IAST/GAL) and detect its galanin (GAL) expression and secretion, a cDNA fragment of rat GAL in plasmid of pBS KS(+)-GAL was inserted into eukaryotic expression vector pcDNA3.1 (+) by DNA recombinant technology, then the restriction enzyme digestion and DNA sequencing were carried out to evaluate the recombinant. The pcDNA3.1 (+)-GAL and pcDNA3.1 (+) construct were transfected into immortalized rat astrocyte strain (IAST) by lipofectamine and the population of cells which stably integrated the construct was selected with 600 microg/mL G418. Individual clones were screened and expanded into clonal cell strains. Detection of Neo gene was used to validate the success of the transfection. Immunocytochemical staining, RT-PCR and radioimmunoassay were used to detect the expression and secretion level of GAL. The recombinant had been successfully constructed by restriction enzyme digestion and DNA sequencing. Detection of Neo gene showed that the pcDNA3.1 (+)-GAL and pcDNA3.1 (+) have been successfully transfected into IAST. After selection by using G418, IAST/GAL and IAST/Neo cell strains were obtained. IAST/GAL, IAST/Neo and IAST were immunostained positively for GAL, but the GAL average optical density of IAST/GAL was significantly higher than that of IAST/Neo and IAST (P0.05). It was concluded that IAST/GAL strain was constructed successfully and it might provide a basis for the further study of pain therapy.

Hormônio do crescimento (GH) e somatomedinas (IGFs). Suas funçöes no metabolismo e no crescimento / Growth hormone (GH) and insulin-like growth factors (IGFs). Their functions on the growth and matabolism

O hormônio do crescimento (GH) é sintetizado e secretado pela adenoipófise atuando no metabolismo e no crescimento. Nesta abordagem säo enfocados vários aspectos do GH, sendo destacados seus controladores no hipotálamo, os caminhos de síntese e liberaçäo e papel no metabolismo e no crescimento associado às somatomedinas. O papel de outras substâncias endógenas e/ou exógenas, que pode alterar os mecanismos de açäo e funçäo do GH, o papel dos fatores de crescimento e suas proteínas transportadoras, os fatores ambientais, que podem almentar os ciclos do GH em pessoas normais, e de que modo o GH é controlado em algumas anomalias genéticas também säo evidenciados.(au)

Galanina e doenca de Alzheimer / Galanin and Alzheimer's disease

Estudos recentes tem sugerido a participacao da galanina na fisiopatologia de algumas doencas neuropsiquiatricas, tais como a doenca de Alzheimer, a esquizofrenia e a anorexia nervosa. A galanina e um neuropeptideo largamente distribuido nos sistemas nervoso central e periferico, presente de forma expressiva no prosencefalo de varios mamiferos. Modelos animais ...

Changes of neuropeptides immunoreactivity according to dehydration in paraventricular nuclei / 대한해부학회지

Dehydration induced an increase in plasma osmotic pressure that causes the release of the neurohypophysial hormone (Vasopresin, Oxytocin) which are synthesized in neurons of the paraventricular (PVN) and supra optic (SON) nuclei in the hypothalamus. On the other hand, PVN which plays an important role as an integration site for the neuroendocrine and autonomic nervous system neurons responded to osmotic stimulation. In this experiment, we studied that the change of several neuropeptidies (AVP: arginine vasopressin, CRF: cor-ticotrophin releasing factor, GAL: galanin, NT: neurotensin. NPY: neuropeptide Y) immunoreactivity in the PVN according to the dehydration. The body weight of the rats decreased during dehydration and various changes were detected in hypothalamic neuropeptidies immunoreactivity.Our results show that: 1. Dehydration significantly increased AVP, CRF and GAL immunoreactivity in the PVN. 2. Dehydration slowly decreased NT immunoreactivity in the PVN. 3. NPY immunoreactive cell bodys were appeared during dehydration which did not observed in PVN at normal group.

Double Immunohistochemical Studies on Distribution and Coexistence with Putative Neurotransmitters and Calretinin in Trigeminal Ganglion of Korean Native Goat / 대한해부학회지

The present study was undertaken to investigate the morphological characteristics of trigeminal ganglion in Korean native goat (Capra hircus) by immunohistochemical methods. The calcitonin gene-related peptide (CGRP), substance P (SP), galanin (GAL) and calretinin (CR) immunoreactivities by immunohistochemical method were observed in the neurons of trigeminal ganglion with populations of 43.75%, 26.01%, 4.98%, and 14.33%, respectively. In double immunohistochemical study, CGRP immunoreactivity was proven to be present in SP (93.93%) and GAL (100%) immunoreactive neurons. SP immunoreactivity was observed in CGRP (36.12%) and GAL (100%) immunore-active neurons. GAL immunoreactivity was colocalized with 8.14% of CGRP and 15.47% of SP immunoreactive neurons. However, CR immunoreactivity was not observed in CGRP, SP and GAL immunoreactive neurons. These findings exhibit that Korean native goat differs from other mammalian species in the distribution and localization of neurochemical substances in trigeminal ganglion, and suggest that these differences may be related with neuroanatomical characteristics.

The Study of the Effect of Nerve Growth Factor on Intestinal Peristalsis in Streptozotocin-Induced Diabetic Rats / 대한해부학회지

Recently, it has been postulated that diabetic autonomic neuropathy is caused by reduction in availability of nerve growth factor (NGF) in enteric nervous system. This experiments were performed to determine the changes of the distribution of enteric neuropeptide by diabetes and these changes could be prevented by administration of NGF. Sprague Dawley rats (200~250gm) were made diabetic by a single intraperitoneal injection of streptozotocin 65 mg/kg in saline. Recombinant human NGF (Sigma, Co., Ltd.) were administered at a dose of 500ng/kg subcutaneously every day for consecutive 4 weeks after streptozotocin administration. After 4 weeks, rats were anesthetized with ether and perfused with 4% paraformaldehyde. ileum was dissected and prepared by whole mount preparation method. Prepared segments were immunostained for substance p, calcitonin gene-related peptide, vasoactive intestinal peptide, and galanin by PAP technique. For the observation of the interstitial cells of Cajal, segments were immersed in Champy-Maillet solution for 2 days Results obtained were as follows: 1. In myenteric plexus of diabetic rats, substance P-like and VIP-like immunoreactivity were not changed compared with that of the control group. CGRP-like and galanin-like immunoreactivity were decreased in diabetic group and immunoreactive cells for CGRP and galanin were also decreased 18.1% (P<0.01) and 43.7% (P<0.01) respectively. 2. In NGF administerd diabetic group, immunoreactivity of substance p, VIP, galanin in myenteric plexus were slightly increased and immunoreactive cells for substancre p, VIP, galanin were almost the same as that of the control group. However, immunoreactive cells for CGRP of myenteric plexus were not changed by NGF. 3. In submucous plexus of diabetic rats, immunoreactivity of all four neuropeptides(substance p, CGRP, VIP, galanin) were decreased compared with that of the control group. Immunoreactive cells for substance p, CGRP, VIP, and galanin were also decreased in 38.8%, 77.6%, 33.0%, and 35.7%, respectively (P<0.01). 4. In NGF administered diabetic group, immunoreactivities of substance p, VIP and galanin in submucous plexus were increased and the immunoreactive cells were increased significantly compared to diabetic group. However, immunoreactive cells for CGRP of submucous plexus were not changed by NGF. 5. Interstitial cells of Cajal of diabetic group were decreased 7.4% ovoidal cells (A type) and 28.3% round cells (B type) In NGF administered group, the morphology and the number of ICC were not different to the control group. With the above results, it could be assumed that NGF prevent the damage of neurotransmitter and ICC in enteric nervous system.

Lactation inhibits the potentiating effect of galanin upon the GnRH-induced LH release observed in diestrous-1 rat

Recent demonstrations of no changes in hypothalamic gonadotropin releasing hormone (GnRH) gene expression nd GnRH levels detected at the pituitary gland in diestrous and lactating rats, indicate that lactational hypogonadotropism in this species is not associated with inhibition of hypothalamic GnRH synthesis and secretion. Hypothalamic galanin potentiates GnRH effects on luteinizing hormone (LH) secretion in male and cycling rats. To explore the interaction between GnRH and galanin during lactation, we studied in vitro the effects of pulsatile stimulation with those peptides upon LH synthesis and secretion from rat pituitaries on diestrous 1 or day 10 of lactation. Hemipituitaries were separately incubated in 1 ml Dulbecco's Minimal Essential Medium supplemented with 1 per cent penicillin-streptomycin and fetal calf serum, at 37 degrees Celsius in 5 per cent CO2-air. The hemipituitaries were stimulated during 12 h with hourly pulses, 6 min each, of (a) gonadotropin releasing hormone (GnRH 25 ng/pulse), (b) rat galanin (600 ng/pulse), (c) GnRH plus galanin, or (d) saline. Medium was collected before each pulse to determine LH by radioimmunoassay. After the 12 h pulsatile regime total RNA was extracted and both actin and beta-LH mRNA were determined by reverse transcriptase polymerase chain reaction. There was a significant stimulation of LH secretion by GnRH (ANOVA, p<0.001) without significant differences between diestrous and lactation pituitaries. Galanin alone did not modify LH secretion but it potentiated the effect of GnRH upon pituitaries from diestrous (p=0.036) but not lactating rats. Neither peptide alone or its combination modified pituitary beta-LH mRNA levels. Results show that galanin regulates differently the secretion and synthesis of LH at the pituitary level. The disappearance of galanin-induced potentiation of GnRH effects upon LH secretion during lactation might contribute to the hypogonadotropism of lactation in the rat.

The Effects of Gonadectomy and Prenatal Testosterone Injection on Galanin Immunoreactive Cells in the Medial Preoptic Area of Rats / 대한해부학회지

Within the medial preoptic area[MPOA], several cytoarchitectonically defined cell groups are sexually dimorphic in their morphology. Specially, the sexual dimorphic nucleus of the preoptic area[SDN-POA] is reported an example of a morphological sex difference in the rat hypothalamus which is influenced by gonadal steroid hormones. Thus, we detemined the distribution of Galanin-immunoreactive[Gal-I] cells and fibers within MPOA and their morphological response to gonadal steroids which is influenced by gonadectomy or prenatal restosterone treatments were observed. The Gal-I cells were appeared within the medial preoptic area. In the males, the volume and number of Gal-I nerve cell bodies were greater than that of females. But the female which treated prenatal testosterone injection had many Gal-I neurons than infact female. And the males that decreased the volume of gonadal hormone by gonadectomy were decreased the volume and number of Gal-I neurons than that of normal males. These results suggest that galaninergic cells within the medial preoptic area are influenced by gonadal steroid hormone[testosterone] in the regulation of sexually dimorphic function.

Galanina, un nuevo neuropéptido. Revisión / Galanina, a new neuropeptide. review

La galanina es un péptido que consta de 29 aminoácidos originalmente aislado de intestino de porcino. Se sintetiza inicialmente como parte de una proteína mayor precursora (preprogalanina). En todas las especies, la porción N-terminal se conserva completamente. Sin embargo, la región C-terminal se modifica ligeramente. Algunas de las características fisiológicas de la galactina son contraer preparaciónes aisladas de fundus, ileo, colon y vejiga urinaria e induce hiperglucemia ligera y sostenida. Su administración estimula el consumo de alimento y tiende a aumentar las concentraciones plasmáticas de la hormona de crecimiento, de prolactina y disminuye la concentración de dopamina. Los estrógenos estimulan dramáticamente la síntesis de ARNm para la galanina y la subsecuente síntesis del péptido. La amplia distribución de la inmunoreactividad semejante a galanina y su localización en los gránulos neurotransmisores sugieren que la galanina puede funcionar como neurotransmisor. Sin embargo, la detección de la inmunorreactividad semejante a galanina después de la estimulación con 17 ß-estradiol sugiere que la galanina hipofisiaria tiene un blanco a distancia, por lo que puede ser una hormona adicional de la hipófisis anterior. Debido a que la galanina se ha localizado en los tejidos reproductivos, parece jugar un papel mediado por estrógenos en la función hipotalámica e hipofisiaria

Galanin-like immunoreactive expression in the central nervous system of the toad

The distribution of galanin (GAL)-like immunoreactivity (-LI) was studied in the CNS of the toad (Bufo arenarum Hensel). Tissue sections were incubated with antibodies directed toward rat or porcine GAL and processed either for the avidin-biotin complex, or for the indirect immunofluorescence techniques. In the telencephalon GAL-immunoreactive (-IR) perikarya were observed in the ventral part of the striatum and in the septal accumbens nuclei. Immunopositive neurons were also observed in the medial amigdala with some intermingled cells between the fibers of the anterior commissure. Numerous GAL-IR perikarya were present along the rostrocaudal medial preoptic nucleus. Occasionally lightly immunoreactive cells were detected in the magnocellular region. The most numerous accumulation of GAL-IR cells was present in the ventral hypothalamus around the infundibular region, in the posterior tubercle and in the nucleus of the paraventricular organ. Immunostained cells were also present in the pretectal gray, solitary nucleus, gracil nucleus and in the spinal cord in the intermediate gray and in large motoneurons of the ventral horn. The widespread distribution found of GAL-LI suggests that GAL in the toad, as well as in mammalian species, may serve a variety of functions with a preponderant role in neuroendocrine processes. A role for GAL as a trophic factor in the brain of the toad is also suggested.

Characteristics of Potassium Channel in the Isolated Rat Detrusor Muscle / 영남의대학술지

The purpose of this study was to investigate the characteristics or the potassium channels existing in the rat urinary bladders. Smooth muscle strips of rat detrusor urinae were examined by isometric myography. Relaxation responses of detrusor muscle strips to the three potassium channel openers pinacidil, a cyanoguanidine derivative, BRL 38227, a benzopyran derivative and RP 52891, a tertrahydrothiopyran derivative were examined. The potassium channel openers reduced the basal tone, and the rank order of potency was RP 52891>pincidil>BRL 38227. Procaine, an inhibitor of the voltage-sensitive potassium channel tended to increase the basal tone, but it did not affect the relaxant effects of the calcium-activated potassium channel opener did not antagonize the relaxant effects, but it reduced the Emax of RP 52891 and BRL 38227. Glibenclamide, an inhibitor of the ATP-sensitive potassium channel, antagonized the relaxant effects of pinacidil, RP 52891 and BRL 38227 reducing the Emax of RP 52891 and BRl 38227. Galanin which inhibits secretion of insulin through opening the ATP-sensitive potassium channels in pancreatic β-cells rather increased the basal tone of the isolated detrusor strips. These results suggest that the urinary bladder of the rat has mainly the ATP-sensitive, glibenclamide sensitive potassium channel, which is a different type from that in the pancreatic β-islet cells.